In the diuretic phase, how are potassium (K+) levels typically affected?

During the diuretic phase, potassium levels typically fall due to the increased excretion of potassium in the urine as a result of diuretic use or conditions that promote diuresis. In this phase, the kidneys excrete excess fluid, and along with water, electrolytes such as potassium are also lost. This can lead to hypokalemia, a condition characterized by abnormally low potassium levels in the blood, which can have significant physiological effects because potassium is crucial for muscle contractions, nerve function, and maintaining proper heart rhythm.

The other options describe states that are not characteristic of the diuretic phase. A rise in potassium levels or unchanged levels would not be expected during this phase due to the increased renal excretion associated with diuresis. Fluctuating levels may occur in some scenarios but would not define the typical response observed during the consistent loss of potassium in the diuretic phase.